Fix Twitter detection on iOS 6; fix share dialog cancel button on iOS 4

Previous behavior checked only for iOS 5 and failed on 6, hiding the Twitter button.
Also, when Twitter button was hidden (eg on iOS 4 as well presumably) the cancel button triggered "Share via mail" whoops
bug 40256: make app run natively on iPhone 5 4" screen

Have to add a splash screen background for this size/resolution or we end up letterboxed to 640x960.
win8: adjust hub listview structure to set 50px margin on bottom.

Tiles are slightly less tall on this screen now.
Hide pin/unpin and find commands on non-article views
win8: Add page transition animation on page transitions
win8: Auto-size title text
Localisation updates from http://translatewiki.net.
Localisation updates from http://translatewiki.net.
Merge branch 'master' of https://github.com/wikimedia/WikipediaMobile
Update versions on win8 app
Win8: Load the featured picture of the day larger
Merge branch 'master' of https://github.com/wikimedia/WikipediaMobile
Win8: load higher-resolution images for featured articles

These are usually tiny thumbnails in the feed; double the size to fit better.
Win8: high-resolution screenshots for store, promo use

Taken in simulator at 2560x1440.
Win8: scalable SVG remasters of store promotional images
Win8 store screenshots: swap hub image with "sexier" one with a color image as the featured
Added more font size choices
Remove Font Size labels
Merge pull request #285 from yuvipanda/more-font-sizes

Added more font size choices

Choices are now: 100%, 150%, 200%, 300%

300% is HUGE and should work for folks with very poor eyesight. :) This removes the old "smaller" size which was 75%, which we don't think anybody really wanted.
Merge pull request #283 from brion/iphone5

bug 40256: make app run natively on iPhone 5 4" screen